1. Field of the Invention
The present invention relates to a spindle motor.
2. Description of the Related Art
Prevalent examples of recording media that write and read images, sounds, and other types of data at high density include optical discs, hard discs, cards, and tapes; and of these, optical discs are at the forefront of the mainstream.
The field of optical discs includes products ranging from laser discs (LD) and compact discs (CD) to digital versatile discs (DVD).
Optical discs can be generally categorized into CDs and DVDs; CDs can be divided into CD-read only memory (CD-ROM) and CD-Rewritable (CD-RW); and DVDs can be split into DVD-ROMs and DVD-random access memory (RAM).
Such optical discs have tracks formed to spiral outward from the middle, whereon digital data of a predetermined format is written.
An optical disc apparatus for reading optical discs has a built-in spindle motor that spins an optical disc at high speed. The optical disc apparatus also includes a built-in actuator, which has a laser diode, a lens, a beam splitter, a photodetector, and other installed optical devices.
A spindle motor according to the related art includes a rotor and a stator. The stator has a bearing housing installed for holding a bearing in place.
However, the bearing housing of a spindle motor according to the related art is a separate component, so that it must be installed following its manufacture. Therefore, the number of manufacturing processes increases due to the installing of the bearing housing.
Also, a bearing housing according to the related art has a plurality of coupling portions formed thereon to couple it to the spindle motor, which complicates the configuration of the bearing housing and increases its size. Consequently, it is difficult for the device to satisfy the prevailing trend of miniaturizing spindle motors, while at the same time securing adequate interior space for ensuring that the motor's capabilities are not compromised.
Also, to prevent the rotating shaft and the rotor yoke from rising, a spindle motor according to the related art employs a washer assembled at its rotating shaft and bearing. Because this configuration does not allow facile assembly of the washer, not only does the assembly process of the unit become more complex, but also the structure does not allow for adequate interior space inside the spindle motor to secured.
Additionally, in spindle motor designs according to the related art, the gaps present between the bearing housing, the rotating shaft, and the upper portion of the bearing induce oil leakage.